Is T61.8X4S a billable ICD-10-CM code?

Yes. T61.8X4S is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does T61.8X4S sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).

What cannot be coded together with T61.8X4S?

T61.8X4S carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T61.8X4S (T61) and apply to it just the same.

T61.8X4S

T61.8X4S — Toxic effect of other seafood, undetermined, sequela

Billable / specific codeICD-10-CMPOA exempt

T61.8X4S is a billable, specific ICD-10-CM code for toxic effect of other seafood, undetermined, sequela. It is valid for submission on a claim.

7th character "S" — sequela

The appropriate 7th character is to be added to each code from category T61

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 inherited from the categories above T61.8X4S

These are not written on T61.8X4S, but they bind it: a note on a category applies to every code beneath it. Billing T61.8X4S with anything listed here is a denial.

Written on T61 — Toxic effect of noxious substances eaten as seafood

allergic reaction to food, such as:
anaphylactic reaction or shock due to adverse food reaction (T78.0-)
bacterial foodborne intoxications (A05.-)
dermatitis (L23.6, L25.4, L27.2)
food protein-induced enterocolitis syndrome (K52.21)
food protein-induced enteropathy (K52.22)
gastroenteritis (noninfective) (K52.29)
toxic effect of aflatoxin and other mycotoxins (T64)
toxic effect of cyanides (T65.0-)
toxic effect of harmful algae bloom (T65.82-)
toxic effect of hydrogen cyanide (T57.3-)
toxic effect of mercury (T56.1-)
toxic effect of red tide (T65.82-)

Risk adjustment

T61.8X4S does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

T61.8X4S is named in 1 Medicare coverage policy — 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56612Billing and Coding: CT of the Head

Code history

T61.8X4S has not changed since FY2024 — no addition, revision or deletion across the FY2024–FY2027 ICD-10-CM releases.

Related codes at this level

Codes that share T61.8X4. If T61.8X4S is not quite right, the correct code is usually one of these.

Questions about T61.8X4S

Is T61.8X4S a billable ICD-10-CM code?: Yes. T61.8X4S is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T61.8X4S sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).
What cannot be coded together with T61.8X4S?: T61.8X4S carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T61.8X4S (T61) and apply to it just the same.